A new biokinetic model, named Hwang model, has been considered to account for the substrate inhibitory effects in microbial growth processes. Its main advantage is flexibility, i.e. its ability to fit experimental data which corresponds to diverse inhibition patterns including concave, convex, and linear as well as linear decrease with inhibition-threshold. performances are compared on the basis of the goodness of fit, the parameter sensitivity analysis, and the best-fittings of different experimental data in the literature, respectively. Finally, Hwang model turns out to be flexible enough for overall validation of microbial inhibition phenomena.